Container



April 12, 1949. sMlTH 2,466,666

CONTAINER Filed Feb. 18, 1947 HARRY EQSMITH.

by X fl fi wwq ATTORNEYS with a forming channel in the Patented Apr. 12, 1949 CONTAINER Harry E. Smith, Little Silver,

N. J., assignorto Celanese Corporation oi America, a corporation of Delaware Original application J 600,346. Divided and une 19, 1945, Serial No. this application February 18, 1947, Serial No. 729,377

1 Claim.

This invention relates to a plastic container comprising a cylindrical body and a beaded open end, together with a beaded cover for fitting over said beaded open end. This application is a division of my application S. No. 600,346, filed June 19, 1945, wherein is claimed a novel apparatus for forming beaded containers and covers therefor.

An object of this invention is to provide a beaded plastic container body and headed plastic cover therefor of such construction as to permit easy closure and to provide a very tight or vacuum fit when the beaded plastic container body is closed by the beaded cover.

Other objects and advantages of this invention will appear from the following detailed description and drawing.

In its broadest aspect, the heading apparatus of this invention comprises a holder for a cylindrical plastic body adapted to be rotated and a heated forming or beading plate of novel design, the rotating holder being arranged to bring the edge of the cylindrical plastic body into contact beading plate.

In the accompanying drawing wherein a preferred embodiment of the beading apparatus of this invention is shown,

Figure 1 is a vertical moss-sectional view ofthe beading apparatus showing a plastic container body, the open end of which is to be beaded,

being held therein, the beading plate being designed to produce an internal bead, and

Figure 2 is a vertical cross-sectional view showing a beading plate designed to produce an external bead and a cover which has been externally beaded.

Like reference numerals indicate like parts throughout both views of the drawing.

Referring now to the drawing for a detailed invention, the reference spindle of metal or other suitable material adapted to be rotated, raised or lowered by suitable means (not shown). die 3 is provided with an aperture 4 to receive a projection 5 of a support 6 to which is attached, as by screws 7, a cylindrical holder 8 for be beaded indicated by reference numeral 9. The projection 5 is held in the spindle aperture l by means oi. screw bolts ll. Supported by holder 8 and held in position therein by means of a screw i2 is a locating block II, the thickness of which depends upon the height 01' the plastic body being operated upon. The locating block may be made of a single thickness of material or may be built up of a number of layers description of of varying thicknesses The thickness of the ocating block l3, in a single layer or in multiple layers, should be such that of an inch of the Side walls protrudes below the bottom of the holder 8 when the plastic body being beaded is the outer wall l8 being of greater length than the inner wall i 9 and both of the walls being substantially parallel with each other. Theforming channel of this invention not only produces a at 2|, on the open end of The beading metal and is rial, such as Masonite or similar material, and is insulated from said base plate 25 by means of an asbestos gasket 26. The base plate 25 may be rigidly fastened to the bed of the heating members in proper alignment with the holder 8 by bolts inserted in holes 21 provided in said base plate. is shown a beading plate 28 for producing an external bead 29 on a cover 3| for the plastic-container In this beading plate, the side walls of the forming channel 32 are tapered outwardly and as in forming channel II the sidewalls are substantially parallel with each other; however, inner side wall 33 is longer than the outer side wall 34. The construction of the forming channel 32 also efl'eets a shaping action on the wallet said cover, causing the wall to 6B taper outwardly from tnebead as shown in the conducting mate-' drawing, forming an angle of about from the vertical.

when the cover 3|, beaded and shaped in accordance with this present invention, is placed on the container body 9, headed and shaped in accordance with this invention, there is produced a very tight or vacuum fit making the same particularly useful as container for face powder and like finely divided materials.

In operation, a plastic body 8 is inserted in holder 8 and is rotated by suitable means operatively connected to spindle 3 at a speed of about 750 R. P. M. The spindle and holder are then lowered by any suitable means until the edge of the container body contacts the tapered side l8 (side 33 in Figure 2) of the forming channel II in beading plate IS. The further downward travel of the rotating spindle 3 carries the edge of the plastic body along tapered side l8 and completely around the circumference of the forming channel of the beading plate I6, which is preferably maintained at a temperature of about 290 F. by means of the heating unit 23, until the bottom surface 34 of holder 8 bears firmly on the outer top surface 35 of heading plate It, thus forming a complete internal bead and at the same time, as the result of the inward forming action on the container side wall on the tapered side l8, in association with the contractive effect of the bead, imparts a slight inward taper of about from the vertical on the wall of the plastic body to a. point about V; of an inch from the beaded portion. The spindle 3 is then raised and the headed and shaped container body is removed from holder 8.

In the heading of plastic container bodies or covers, as heretofore commonly practiced, the forming channel was positioned at right angles to the upper face of the beading plate. dimensional relation between the outside diameter of the forming channel at the beginning of the radius and the outside diameter of the unbeaded side wall was such that the side wall of the fully beaded body or cover was positioned at right angles to the horizontal plane of the closed end. Therefore, in accordance with prior practice, the side wall of the internally beaded bodies and the externally beaded covers being positioned at right angles to the horizontal plane of the closed ends resulted in a vertical telescopic fit between the outer surface of the body and the inner surface of the cover. No provision was made for variables in the expansion and contraction characteristics of the plastic. Accordingly, for a constantly tight closure in the finished and closed container entire dependence was placed upon a close dimensional fit.

With the present invention, however, many advantages flow from the use of the improved beading apparatus, particularly the improved construction of the forming channel. Thus, there are produced cylindrical shaped plastic container bodies and covers, from the same die assembly,

. with internally or externally beaded open ends that effect a highly satisfactory fit. This is due to the fact that the dimensional relation between the outside diameter of the unbeaded body. or the Thus, the

inside diameter of the unbeaded cover, and the diameter of the forming channel at the beginning of the bead radius, the 20 taper of the forming channel above the bead radius in association with the contractive eifect from the plastic of the beaded operation, result in completed containers with fully beaded and slightly tapered open ends which permit of an easy closure and which forms a very tight or vacuum fit and provides for normal dimensional variation so as to constantly maintain a tight closure.

The container bodies and covers beaded and shaped in accordance with the present invention may have a basis of any suitable thermoplastic film or sheet material. For example, the container bodies and covers may be made from thermoplastic material containing nitrocellulose of any suitable degree of nitration, or an organic derivative of cellulose such as organic esters of cellulose and cellulose ethers. Examples of organic esters of cellulose are cellulose acetate, cellulose propionate and cellulose butyrate, while examples of cellulose ethers are ethyl cellulose and benzyl cellulose. The container bodies and covers may also be made from mixed esters of cellulose, such as cellulose aceto-propionate, cellulose aceto-butyrate, or ether esters of cellulose, such as ethyl cellulose acetate. Film or sheet material of thermoplastic synthetic resins and polymerization products may also be employed for producing container bodies and covers in accordance with this invention.

It is to be understood that the foregoing detailed description is merely given by way of illus r tration and that many variations may be made therein without departing from the spirit of my invention.

Having described my invention, what I desire to secure by Letters Patent is:

A plastic container comprising a cylindrical body having an internally beaded open end and an inwardly tapered portion adjacent to said beaded end and a cover for said cylindrical body, said cover having an annular flange forming a wall inwardly tapered toward its free edge and terminating in an externally beaded open end, the depth of the flange being greater than the width of the inwardly tapered portion of the body, said cover having an internal diameter at the beaded end substantially the same as the external diameter of the body below the tapered portion of said body, whereby when the cover is applied to the body the beaded portion of the. cover extends below the tapered portion of said body to form a tight or vacuum fit.

' HARRY E. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 123,837 Patterson Feb. 20, 1872 1,193,461 Hisg en et al. Aug. 1, 1916 1,266,685 Hothersall May 21, 1918 2,099,056 Ferngren Nov. 16, 1937 

